1. Technical Field
This invention relates to an apparatus for producing high-speed rotation and, in particular, to an electrical motor for rotating a shaft.
2. Background Art
The electrical motor mentioned above with one rotational axis has a rotor and a stator secured to a fixed member disposed on a motor housing so that the rotary shaft of the motor is rotated by the electromagnetic action between a set of the rotor and the stator.
In the motor mentioned above, any motor output, e.g. rotational frequency, depends on magnetic action between a set of the rotor and the stator. Therefore, the rotational frequency of a high-speed rotation motor is Inevitably limited in view of electromagnetic characteristics. Furthermore, the high-speed rotation motor requires a high rotational frequency at the bearing receiving the rotary shaft, thereby causing cooling and lubricating of the bearing for the rotary shaft to be difficult. Therefore, the rotational frequency of the motor is further limited.